- All other females must had either a hysterectomy or bilateral oophorectomy at least 6 months before screening (proper documentation required) OR been naturally postmenopausal for at least 24 consecutive months (i.e. who has not had menses at any time in the preceding 24 consecutive months). For this study, in subjects who are postmenopausal, estradiol level must be <30 pg/mL and plasma FSH must be >40 IU/L at screening.